Add APIv2 support to make host optional on evacuate

[OpenStack Infra]

https://review.openstack.org/88749
commit d5a70de4793a1e44056c55121505edc63fd36969
Author: Leandro I. Costantino <email address hidden>
Date: Sat Feb 8 12:23:30 2014 -0300

    Add APIv2 support to make host optional on evacuate

    In the event of an unrecoverable hardware failure, support needs to
    relocate an instance to another compute so it can be rebuilt.

    The changes involved in this patch are:
      [*] Add a new v2 extension to determine that the host argument
          on evacuate is now optional.(Extended_evacuate_find_host)
      [*] Doc regeneration.

    DocImpact: The evacuate target host is now optional.
    If 'host' field is not sent in the request, the scheduler will
    determine the target host.
    This will include nova client changes ( on the proper commit ) to support
    this new optional parameter.

    Implements: blueprint find-host-and-evacuate-instance

    Change-Id: Ib34fb3120263b746ad2f8fe89c14137e36a07a53
    Co-Authored-By: Juan M. Olle <email address hidden>
    Co-Authored-By: Andres Buraschi <email address hidden>
    Co-Authored-By: Anuj Mathur <email address hidden>
    Co-Authored-By: Navneet Kumar <email address hidden>
    Co-Authored-By: Claxton Correya <email address hidden>

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/230221

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/230221
Committed: https://git.openstack.org/cgit/openstack/api-site/commit/?id=1f09e477f7e5097d6275f4d4412bb0cb96e35967
Submitter: Jenkins
Branch: master

commit 1f09e477f7e5097d6275f4d4412bb0cb96e35967
Author: Atsushi SAKAI <email address hidden>
Date: Fri Oct 2 09:09:54 2015 +0900

    Change host attribute to optional on evacuate

      Compute API v2 is already fixed.
      This patch makes host attribute optional on
      Compute API v2.1.

    Change-Id: I83ec741cbeaf9d7c6bba5baf252fe67d8f0c9500
    Closes-Bug: #1346652